Process for producing flexible polyurethane foam using natural oil polyols

ABSTRACT

A composition and process useful to make flexible polyurethane foams and in particular flexible molded polyurethane foams is disclosed. The usage of dipolar aprotic liquids such as DMSO, DMI, sulfolane, N-methyl-acetoacetamide, N,N-dimethylacetoacetamide as well as glycols containing hydroxyl numbers OH#≦1100 as cell opening aides for 2-cyanoacetamide or other similar molecules containing active methylene or methine groups to make a polyurethane foam is also disclosed. The advantage of using cell opener aids results in a) no foam shrinkage; b) lower use levels of cell opener; c) foam performance reproducibility d) optimum physical properties. In addition, combining the acid blocked amine catalyst together with the cell opener and the cell opener aid results in a less corrosive mixture as well as provides a method that does not require mechanical crushing for cell opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims the benefit of U.S. Patent Application No.61/505,259, filed on Jul. 7, 2011. The disclosure of Application No.61/505,259 is hereby incorporated by reference. The subject matter ofthe instant invention is related to U.S. patent application Ser. No.13/178,558 filed on Jul. 8, 2011 and entitled “Additives for ImprovingPolyurethane Foam Performance”. The disclosure of this application ishereby incorporated by reference.

BACKGROUND OF THE INVENTION

The subject matter of the instant invention relates to compositions andmethods used for making foam; particularly polyurethane foam obtained byusing natural oil polyols.

Flexible molded foams are conveniently produced using tertiary aminecompounds that can catalyze the reaction between water and isocyanate(blowing reaction) and between alcohol and isocyanate (gellingreaction). In some particular cases where molded foam parts areproduced, delay action catalysts can be more conveniently used becausethey provide the advantage of slower reactivity during the pouringprocess. These catalysts are composed of a tertiary amine that have beenreacted (or blocked) with an organic acid. As heat is evolved during thepolymerization reaction, dissociation of the tertiary amine salts to thetertiary amine catalysts and acid can occur thereby causing the foam tocure. Foam produced in this manner is normally characterized by thepresence of a relatively high percentage of closed polyurethane cellscausing the foam to shrink when cooling due to its poor dimensionalstability.

In order to maintain the dimensional stability the catalysts or acidblocked catalysts were combined with cell openers in an aqueous system.U.S. Pat. No. 6,136,876 and U.S. Pat. No. 6,248,801 discloses a methodfor making polyurethane foam in which a polyisocyanate is reacted with apolyol in the presence of a urethane catalyst, a blowing agent,optionally a silicon surfactant cell stabilizer and a cell openingadditive. The cell opening additive comprises a substance containing anactive methylene or methine group. The cell opener can be delivered as aneat liquid or dissolved in one of the components of the formulationsuch as the surfactant, water, crosslinker, polyol, amine catalyst orcatalysts. One example of cell opener containing active methylenicgroups is 2-cyanoacetamide. The main disadvantages of dispensing2-cyanoacetamide in the polyol, crosslinker, surfactant, amine catalystor catalysts or mixtures of any of the components used in theformulation is the no solubility or negligible solubility of2-cyanoacetamide. Some amine catalysts or crosslinkers can even reactwith 2-cyanoacetamide causing the release of ammonia or the formation ofcolored products. Water could be used as the sole solvent to dispense2-cyanoacetamide in a polyurethane formulation. However there are a fewdisadvantages when using water as solvent including: a) poor solubility;b) reduced the cell opening efficiency (requiring higher use level ofcell opener); c) foam shrinkage, and; d) poor reproducibility. Otherconventional chemical methods for controlling foam shrinkage havedrawbacks such as requiring high levels of cell opener (often as high as1-5 pphp) and/or adversely affecting the physical properties of foamand/or using environmentally undesirable substances and/or usingmaterials that are very difficult to dispense in a liquid form to apolyurethane foam system.

Shrinkage of flexible molded polyurethane foam may also be controlled byusing mechanical crushing to open foam cells and improve dimensionalstability of foam. Current mechanical methods for cell opening consistmainly of crushing, vacuum rupture or time pressure release.

Upon demolding of a foam article mechanical crushing and breaking ofpolyurethane foam cells enables the foam to be more dimensionallystable. Another method of breaking foam cells is vacuum-crushing whichinvolves drawing a vacuum on the finished polyurethane product inducingcell rupture. The overall effect of these methods is reduced foamshrinkage.

Other mechanical methods have been used to achieve dimensionally stablefoam, such as decreasing cycle production times. For example, demoldingthe polyurethane foam in three minutes as compare to four minutes willdramatically improve the dimensional stability. Another method forproducing dimensionally stable foams is time pressure release (TPR). TPRcomprises opening the mold during process to release the internalpressure and then reclosing for the duration of the cure time. Thesudden release of internal pressure burst the cell windows, therebyobtaining dimensionally stable foam products.

Mechanical methods usually result in incomplete or inconsistent cellopening and require flexible molded foam producers to invest inadditional machinery.

U.S. Pat. No. 3,314,834 discloses diketo compounds form effectivepotlife extension agents in polyurethane propellants.

U.S. Pat. No. 3,635,906 discloses that certain chelate-forming compoundshave the effect of delaying initiation reaction between an organicpolyisocyanate and an organic polyhydroxy compound in the presence of anamine free organotin cure rate catalyst.

U.S. Pat No. 4,426,510 discloses coating or adhesive compositions havingextended potlife and short cure time comprising an organic polyol, anorganic polyisocyanate, an organozinc cure rate catalyst, and a compoundselected form a) beta-dicarbonyl compounds, b) alpha-hydroxy ketones, c)fused aromatic beta-hydroxy ketones and d) beta hydroxylnitrogen-heterocyclic fused aromatics.

GB 2303372 discloses making polyurethane foams using the mechanicalfrothing technique and a catalyst system comprising a metal acetylacetonate and acetyl acetone.

U.S. Pat. No. 4,721,642 discloses a blocked polyisocyanate prepolymerformed by blocking the terminal —NCO group of the polyisocyanate with ablocking agent such as alcohol, phenol, ethyl acetoacetate,e-caprolactam, MEK oxime, diethyl malonate, acetyl acetone, cyanic acidand sodium bisulfite. A polyurethane resin foamable paint comprises anaqueous dispersion composed of blocked polyisocyante prepolymer,additives, chain extender, foaming agent and emulsifier.

CA 2141890 discloses the production of rigid polyurethane,polyisocyanurate and polyurethane urea foams with HCFC blowing agentsand optionally a flame retardant and/or chelating agent which is acidic,i.e., having a pKa value from 0 to 10.

U.S. Pat. No. 3,972,846 discloses a curable polyurethane compositioncomprising a keto compound and a liquid mixture of an organic aliphaticpolyfunctional polyisocyanate and a compound having active hydrogen.

U.S. Pat. No. 4,251,635 discloses flexible polyurethane foams havingreduced tendency to form burning embers when it is ignited and burned byincorporating a ketone or benzaldehyde into the reaction mixture beforefoaming.

DE 1 005 722 discloses that reaction of polyols with polyisocyanates canbe retarded by adding an imine (the condensation product of a primaryamine and an aldehyde or a ketone or a diketone).

DE 2 451 726 discloses a process for slowing down the reaction ofisocyanates compounds with polyester polyols in which the polyolscontain at least one aldehyde and/or ketone and a mono-amine in themolar ratio of aldehyde or ketone group: amino group from 1:0.1 to 1.

U.S. Pat. No. 6,136,876 discloses a method for preparing flexiblepolyurethane foam by reacting an organic polyisocyanate with a polyol inthe presence of urethane catalyst, water as blowing agent, optionally asilicon surfactant, and a cell opener characterize in that the cellopener comprises an active methylene or methine group containingcompound.

U.S. Pat. No. 6,248,801 discloses a method for preparing flexiblepolyurethane foam by contacting an organic polyisocyanate with a polyolin the presence of urethane catalyst, water as blowing agent, optionallya silicon surfactant cell stabilizer, and a cell opening additive. Thecell opening additive comprises an active methylene or methine compoundwhich also contains a tertiary amine.

Polyols useful in the preparation of polyurethane foam from inexpensiveand renewable resources are highly desirable to minimize the depletionof fossil fuel and other non-sustainable resources. WO01/70842 A2describes the formation of rigid polyurethane foam for insulation usesas the reaction product of a polyol selected from a vegetable oil, amineral oil, a glycol, syrup, or a combination thereof with apolyisocyanate in the presence of a catalyst and at least one blowingagent. US2004/0242910 A1 describes a method to make natural oil polyolmade by reaction of natural oil from vegetal or animal source with amultifunctional hydroxyl compound derived from a natural source such assorbitol in the presence of an alkali metal salt or base such aspotassium hydroxide as catalyst. US2005/0282921 Al provides a cellularmaterial obtained by the reaction of soy-based polyol, petro-basedblowing agent, cross-linking agent, a combination of siliconesurfactants and isocyanate. US2006/0229375 A1 relates to polyurethanefoam made with alkoxylated vegetable oil hydroxylates replacing at leasta portion of the typically used petroleum based polyols.

The disclosure of the previously identified patents and patentapplications is hereby incorporated by reference.

BRIEF SUMMARY OF THE INVENTION

The instant invention solves problems associated with conventionpractice by providing a composition and method for making polyurethanefoam. This invention relates to the benefits of using dipolar aproticliquids such as dimethyl sulfoxide (DMSO),1,3-dimethyl-2-imidazolidinone (DMI), sulfolane,N-methyl-acetoacetamide, N,N-dimethylacetoacetamide as well as glycolscontaining hydroxyl numbers OH#≦1100 as cell opening aides for2-cyanoacetamide or other similar molecules containing active methyleneor methine groups to make polyurethane foam. The advantage of using theinventive cell opener aids results in: a) no (or substantially no) foamshrinkage; b) lower use levels of cell opener; c) foam performancereproducibility; and d) optimum physical properties. In addition,combining an acid blocked amine catalyst together with the inventivecell opener and the cell opener aid can result in a less corrosivemixture as well as provides a method that does not require mechanicalcrushing for cell opening.

The use of these compositions can produce foam with superior physicalproperties including when natural oil polyols (NOPs) are used as rawmaterials. If NOPs are introduced into conventional formulations toreplace conventional polyether polyol, then physical properties such astensile, tear and elongation can deteriorate yielding finished productwith poorer mechanical properties and lower ageing stability. However,this limitation can be overcome by the instant invention when NOPs areused in combination with the additive solutions.

This disclosure relates broadly to a composition and process to makedimensionally stable polyurethane foams. The inventive compositioncomprises a cell opener, a cell opener aid, a tertiary amine catalystand optionally an acid. Examples of suitable acids comprise any organiccarboxylic acids containing any saturated or unsaturated and substitutedor unsubstituted aliphatic or aromatic group with single or multipleacid groups with or without isocyanate reactive groups. Carboxylic acidsare normally added to the polyurethane formulation to slow down theactivity of the tertiary amine and prevent a fast increase in viscositywhich, in the case of molded foams, allows for a more efficientmold-filling operation particularly in cases where molds with complexshapes and geometries are needed. This approach allows filling of smallcavities and voids minimizing the number of defective articles. Acidsmost commonly used for this purpose are monoacids such as acetic acid,propionic acid, butanoic acid, hexanoic acid, 2-ethylhexanoic acid andthe like. Other acids can also be used such as those described U.S. Pat.Nos. 6,387,972 and 6,432,864; hereby incorporated by reference.Additional xxamples of acid comprise formic acid, pentanoic acid,pivalic acid, neoheptanoic acid, neodecanoic acid, neododecanoic acid,2-ethylhexanoic acid, glycolic acid, gluconic acid, salicylic acid,lactic acid, benzoic acid, phthallic acid, phthallic acid monestersobtained from phthallic anhydride with glycols, polyacids such aspolyacrylic acid, mixtures thereof, among others. The inventive processcan enable the production of polyurethane foam by maximizing theefficiency of the cell opener and imparting great dimensional stability.The advantage of the process is that no crushing of foam is requiredafter the product is removed from the mold. This results in scrapminimization and provides products with high quality (high dimensionalstability). Also, using the cell opener aides reduces the effectiveamount of cell opener needed.

One aspect of the invention relates to a composition comprising at leastone NOP, at least one cell opener, at least one cell opener aid, atleast one catalyst and optionally an acid.

Another aspect of the invention relates to a process for makingpolyurethane foam comprising: utilizing a combination of the inventivecompositions in the presence of tertiary amine catalysts or acid blockedtertiary amine catalysts, and to foams obtained from the method andinventive compositions.

DETAILED DESCRIPTION OF THE INVENTION

The inventive composition comprises at least one NOP, a cell openercomprising molecules containing active methylene or methine groups, acell opener aid comprising at least one dipolar aprotic liquid, atertiary amine catalyst and optionally an acid. The inventive processcan enable the production of polyurethane foam by improving cell openerefficiency and, in the case of molded foams, reducing or eliminating theconventional step of crushing of the foam is required after the productis removed from the mold.

Preparation of Foams

Foams of any of the various types known in the art may be made using themethods of this invention, using typical polyurethane formulations towhich have been added a cell opener, a cell opener aid and the aminecatalysts. For example, flexible polyurethane foams with excellentphysical properties described herein will typically comprise thecomponents shown below in Table 1, in the amounts indicated. Thecomponents shown in Table 1 will be discussed in detail below.

TABLE 1 Polyurethane Components Component Parts by Weight Base Polyol  20-100 Polymer polyol NOP 0-80 varied Silicone surfactant  0.5-10Blowing agent    2-4.5 Crosslinker 0.5-2 Catalyst 0.25-10 PolyisocyanateNCO index = 70-115

The amount of polyisocyanate used in polyurethane formulations accordingto the invention is not limited, but it will typically be within thoseranges known to those of skill in the art. An exemplary range is givenin table 1, indicated by reference to “NCO Index” (isocyanate index). Asis known in the art, the NCO index is defined as the number ofequivalents of isocyanate, divided by the total number of equivalents ofactive hydrogen, multiplied by 100. The NCO index is represented by thefollowing formula.NCO index=[NCO/(OH+NH)]*100The NCO index will normally range from about 70 to about 120 andtypically about 80 to about 110.

Flexible foams typically use copolymer polyols as part of the overallpolyol content in the foam composition, along with base polyols of about4000-5000 weight average molecular weight and hydroxyl number of about28-35. Base polyols and copolymer polyols will be described in detaillater herein.

Catalysts

The catalysts of the present invention comprise tertiary amines.Tertiary amine catalysts can contain an isocyanate-reactive group ornot. Isocyanate reactive groups comprise primary amine, secondary amine,hydroxyl group, amide or urea. Tertiary amine catalysts containingisocyanate reactive groups include both gelling and blowing catalysts.Exemplary gelling catalysts includeN,N-bis(3-dimethylamino-propyl)N-isopropanolamine;N,N-dimethylaminoethyl-N′-methyl ethanolamine (DABCO® T, Air Productsand Chemicals, Inc. of Allentown, Pa.); N,N,N′-trimethylaminopropylethanolamine (POLYCAT® 17, by Air Products and Chemicals, Inc.),N,N-dimethylethanolamine (DABCO® DMEA);N,N-dimethyl-N′,N′-2-hydroxy(propyl)-1,3-propylenediamine;dimethylaminopropylamine (DMAPA); (N,N-dimethylaminoethoxy)ethanol,methyl-hydroxy-ethyl-piperazine, bis(N,N-dimethyl-3-aminopropyl)amine(POLYCAT® 15), N,N-dimethylaminopropyl urea (DABCO® NE1060, DABCO®NE1070), N,N′-bis(3-dimethylaminopropyl) urea (DABCO® NE1060, DABCO®NE1070), bis(dimethylamino)-2-propanol, 6-dimethylamino-1-hexanol,N-(3-aminopropyl)imidazole, N-(2-hydroxypropyl)imidazole, andN-(2-hydroxyethyl)imidazole. The amount of tertiary amine will normallyrange from about 0.01 pphp to about 20 pphp and typically from about0.05 pphp to about 10 pphp.

Exemplary blowing catalysts containing isocyanate reactive groupsinclude 2-[N-(dimethylaminoethoxyethyl)-N-methylamino]ethanol (DABCO®NE200), dimethylaminoethoxyethanol andN,N,N′-trimethyl-N′-3-aminopropyl-bis(aminoethyl) ether (DABCO® NE300).The amount of blowing catalyst will normally range from about 0.01 pphpto about 10 pphp and typically about 0.05 to about 5.0 pphp

The catalyst may also comprise tertiary amines that are highly volatileand not isocyanate-reactive. Suitable volatile gelling catalysts mayinclude, for example, diazabicyclooctane (triethylenediamine), suppliedcommercially as DABCO 33-LV® catalyst, tris(dimethyalminopropyl)amine(Polycat® 9), dimethylaminocyclohexylamine (Polycat® 8) andbis(dimethylaminopropyl)-N-methylamine (Polycat® 77). Suitable volatileblowing catalysts include, for example, bis-dimethylaminoethyl ether,commercially supplied as DABCO® BL-11 catalyst by Air Products andChemicals, Inc.; as well as pentamethyldiethylenetriamine (POLYCAT® 5,Air Products and Chemicals, Inc.) and related compositions; higherpermethylated polyamines;2-[N-(dimethylaminoethoxyethyl)-N-methylaminolethanol and relatedstructures; alkoxylated polyamines; imidazole-boron compositions; oramino propyl-bis(amino-ethyl)ether compositions. The amount of theforegoing catalyst will normally range from about 0.01 pphp to about 20pphp and typically about 0.05 pphp to about 10.0 pphp.

The catalyst compositions may also include other components, for exampletransition metal catalysts such as organotin compounds, salts of tin,organobismuth and bismuth salts, for example when the desiredpolyurethane foam is a flexible slab stock. Additional examples of metalcatalyst compriss dibutylin dilaureate, dimethyltin dilaureate,dimethyltin diacetate, dibutyltin diacetate, dimethyltindilaurylmercaptide, dibutyltin dilaurylmercaptide, dimethyltindiisooctylmaleate, dibutyltin diisooctylmaleate, dimethyltinbi(2-thylhexyl mercaptacetate), dibutyltin bi(2-thylhexylmercaptacetate), stannous octate, other suitable organotin catalysts, ora combination thereof. Other metals can also be included, such as, forexample, bismuth (Bi). Suitable bismuth carboxylate salts includes saltsof pentanoic acid, neopentanoic acid, hexanoic acid, 2-ethylhexylcarboxylic acid, neohexanoic acid, octanoic acid, neooctanoic acid,isooctanic acid, heptanoic acid, neoheptanoic acid, isoheptanoic acid,nonanoic acid, neononanoic acid, isononanoic acid, decanoic acid,isodecanoic acid,neodecanoic acid, undecanoic acid, isounecanoic acid,neoundecanoic acid, dodecanoic acid, neododecanoic acid, isododecanoicacid, and other suitable carboxylic acids. Other salts of transitionmetals of lead (Pb), iron (Fe), zinc (Zn) with pentanoic acid,neopentanoic acid, hexanoic acid, 2-ethylhexyl carboxylic acid, octanoicacid, neooctanoic acid, neoheptanoic acid, neodecanoic acid,neoundecanoic acid, neododecanoic acid, and other suitable carboxylicacids may also be included. The amount of metal catalyst, if present,will normally range from about 0.005 pphp to about 20 pphp and typicallyabout 0.01 pphp to about 10 pphp.

Typically, the loading of non-fugitive tertiary amine catalyst(s) formaking foam according to the invention will be in the range of 0.1 to 20pphp, more typically 0.1 to 10 pphp, and most typically 0.1 to 5 pphp.However, any effective amount may be used. The term “pphp” means partsper hundred parts polyol.

Typically, the inventive cell openers and cell opener aids are combinedwith the catalyst prior to making foam. Cell openers can comprise anysuitable molecule containing active methylene or methine groups such asat least one member selected from the group consisting of2-cyanoacetamide, N-methyl cyanoacetamide, N-ethylcyanoacetamide,N-propylcyanoacetamide, N-butylcyanoacetamide,N-hydroxyethyl-cyanoacetamide. The cell opener aid can comprise anysuitable dipolar aprotic liquid such as at least one member selectedfrom the group consisting of DMSO, 1,3-dimethyl-2-imidazolidinone (DMI),sulfolane, N-methyl-acetoacetamide, N,N-dimethylacetoacetamide as wellas glycols containing hydroxyl numbers OH#≦1100. The amount of cellopener typically ranges from about 0.01 pphp to about 2.0 pphp and morepreferably from 0.01 pphp to 1.0 pphp. The cell opener aid typicallyranges from 0.01 pphp to 10 pphp and more preferably from 0.05 pphp to 5pphp.

Organic Isocyanates

Suitable organic isocyanate compounds include, but are not limited to,hexamethylene diisocyanate (HDI), phenylene diisocyanate (PDI), toluenediisocyanate (TDI), and 4,4′-diphenylmethane diisocyanate (MDI). In oneaspect of the invention, 2,4-TDI, 2,6-TDI, or any mixture thereof isused to produce polyurethane foams. Other suitable isocyanate compoundsare diisocyanate mixtures known commercially as “crude MDI.” One exampleis marketed by Dow Chemical Company under the name PAPI, and containsabout 60% of 4,4′-diphenylmethane diisocyanate along with other isomericand analogous higher polyisocyanates. While any suitable isocyanate canbe used, an example of such comprises isocyanate having an index rangefrom about 80 to about 120 and typically from about 90 to about 110.

Polyol Component

Polyurethanes are produced by the reaction of organic isocyanates withthe hydroxyl groups in a polyol, typically a mixture of polyols. Thepolyol component of the reaction mixture includes at least a main or“base” polyol. Base polyols suitable for use in the invention include,as non-limiting examples, polyether polyols. Polyether polyols includepoly(alkylene oxide) polymers such as poly(ethylene oxide) andpoly(propylene oxide) polymers and copolymers with terminal hydroxylgroups derived from polyhydric compounds, including diols and triols.Examples of diols and triols for reaction with the ethylene oxide orpropylene oxide include ethylene glycol, propylene glycol,1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol,diethylene glycol, dipropylene glycol, pentaerythritol, glycerol,diglycerol, trimethylol propane, and similar low molecular weightpolyols. Other base polyol examples known in the art includepolyhydroxy-terminated acetal resins, hydroxyl-terminated amines andhydroxyl-terminated polyamines. Examples of these and other suitableisocyanate-reactive materials may be found in U.S. Pat. No. 4,394,491;hereby incorporated by reference. Suitable polyols also include thosecontaining tertiary amine groups than can catalyze the gelling and theblowing reaction of polyurethanes, for example those described in WO03/016373 A1, WO 01/58976 A1; WO2004/060956 A1; WO03/016372 A1; andWO03/055930 A1; hereby incorporated by reference. Other useful polyolsmay include polyalkylene carbonate-based polyols and polyphosphate-basedpolyols.

In one aspect of the invention, a single high molecular weight polyetherpolyol may be used as the base polyol. Alternatively, a mixture of highmolecular weight polyether polyols, for example, mixtures of di- andtri-functional materials and/or different molecular weight or differentchemical composition materials may be used. Such di- and tri-functionalmaterials include, but are not limited to polyethylene glycol,polypropylene glycol, glycerol-based polyether triols,trimethylolpropane-based polyether triols, and other similar compoundsor mixtures, provided that they are ester-free. In some embodiments ofthe invention, at least 50 wt % of the ester-free polyol componentconsists of one or more polyether polyols.

In addition to the base polyols described above, or instead of them,materials commonly referred to as “copolymer polyols” may be included ina polyol component for use according to the invention. Copolymer polyolsmay be used in polyurethane foams to increase the resistance of the foamto deformation, for example to improve the load-bearing properties ofthe foam. Depending upon the load-bearing requirements for thepolyurethane foam, copolymer polyols may comprise from 0 to about 80percent by weight of the total polyol content. Examples of copolymerpolyols include, but are not limited to, graft polyols and polyureamodified polyols, both of which are known in the art and arecommercially available.

Graft polyols are prepared by copolymerizing vinyl monomers, typicallystyrene and acrylonitrile, in a starting polyol. The starting polyol istypically a glycerol-initiated triol, and is typically end-capped withethylene oxide (approximately 80-85% primary hydroxyl groups). Some ofthe copolymer grafts to some of the starting polyol. The graft polyolalso contains homopolymers of styrene and acrylonitrile and unalteredstarting polyol. The styrene/acrylonitrile solids content of the graftpolyol typically ranges from 5 wt % to 45 wt %, but any kind of graftpolyol known in the art may be used.

Polyurea modified polyols are formed by the reaction of a diamine and adiisocyanate in the presence of a starting polyol, with the productcontaining polyurea dispersion. A variant of polyurea modified polyols,also suitable for use, are polyisocyanate poly addition (PIPA) polyols,which are formed by the in situ reaction of an isocyanate and analkanolamine in a polyol.

Natural Oil Polyol Component

Polyols useful in the preparation of polyurethane foam from inexpensiveand renewable resources are highly desirable to minimize the depletionof fossil fuel and other non-sustainable resources. Natural oilscomprise triglycerides of saturated and unsaturated fatty acids. Onenatural oil polyol is castor oil, a natural triglyceride of ricinoleicacid which is commonly used to make polyurethane foam even though it hascertain limitations such as low hydroxyl content. Other natural oilsneed to be chemically modified to introduce sufficient hydroxyl contentto make them useful in the production of polyurethane polymers. Thereare two chemically reactive sites that can be considered when attemptingto modify natural oil or fat into a useful polyol: 1) the unsaturatedsites (double bonds); and 2) the ester functionality. Unsaturated sitespresent in oil or fat can be hydroxylated via epoxidation/ring openingor hydroformilation/hydrogenation. Alternatively, trans-esterificationcan also be utilized to introduce OH groups in natural oil and fat. Thechemical process for the preparation of natural polyols usingepoxidation route involves a reaction mixture that requires epoxidizednatural oil, a ring opening acid catalyst and a ring opener. Epoxidizednatural oils include epoxidized plant-based oils (epoxidized vegetableoils) and epoxidized animal fats. The epoxidized natural oils may befully or partially epoxidized and these oils include soybean oil, cornoil, sunflower oil, olive oil, canola oil, sesame oil, palm oil,rapeseed oil, tung oil, cotton seed oil, safflower oil, peanut oil,linseed oil and combinations thereof. Animal fats include fish, tallowand lard. These natural oils are triglycerides of fatty acids which maybe saturated or unsaturated with various chain lengths from C12 to C24.These acids can be: 1) saturated: lauric, myristic, palmitic, steric,arachidic and lignoceric; 2) mono-unsaturated: palmitoleic, oleic, 3)poly-unsaturated: linoleic, linolenic, arachidonic. Partially or fullyepoxidized natural oil may be prepared when reacting peroxyacid undersuitable reaction conditions. Examples of peroxyacids utilized in theepoxidation of oils have been described in WO 2006/116456 A1; herebyincorporated by reference. Ring opening of the epoxidized oils withalcohols, water and other compounds having one or multiple nucleophilicgroups can be used. Depending on the reaction conditions oligomerizationof the epoxidized oil can also occur. Ring opening yields natural oilpolyol that can be used for the manufacture of polyurethane products. Inthe hydroformilation/hydrogenation process, the oil is hydroformylatedin a reactor filled with a hydrogen/carbon monoxide mixture in thepresence of a suitable catalyst (typically cobalt or rhodium) to form analdehyde which is hydrogenated in the presence of cobalt or nickelcatalyst to form a polyol. Alternatively, polyol form natural oil andfats can be produced by trans-esterification with a suitablepoly-hydroxyl containing substance using an alkali metal or alkali earthmetal base or salt as a trans-esterification catalyst. Any natural oilor alternatively any partially hydrogenated oil can be used in thetransesterification process. Examples of oils include but are notlimited to soybean, corn, cottonseed, peanut, castor, sunflower, canola,rapeseed, safflower, fish, seal, palm, tung, olive oil or any blend. Anymultifunctional hydroxyl compound can also be used such as lactose,maltose, raffinose, sucrose, sorbitol, xylitol, erythritol, mannitol, orany combination.

NOPs can be used alone or in combination with the previously describedpolyols. Polyols amounts are defined by pphp. There are typically 3types of polyols above defined: standard polyol or polyether polyolwhich can be used in the range of about 100 pphp (the only polyol) toabout 10 pphp. The copolymer polyol (CPP) can be used in the range ofabout 0 to about 80 pphp. Finally the NOP (natural oil polyol) whichtypically can be present from about 0 to about 50 pphp.

Blowing Agents

Polyurethane foam production may be aided by the inclusion of a blowingagent (BA) to produce voids in the polyurethane matrix duringpolymerization. Any suitable blowing agent may be used.

Suitable blowing agents include compounds with low boiling points whichare vaporized during the exothermic polymerization reaction. Suchblowing agents are generally inert or they have low reactivity andtherefore it is likely that they will not decompose or react during thepolymerization reaction. Examples of blowing agents include, but are notlimited to, carbon dioxide, chlorofluorocarbons (CFCs),hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs),fluoroolefins (FOs), chlorofluoroolefins (CFOs), hydrofluoroolefins(HFOs), hydrochlorfluoroolefins (HCFOs), acetone, and low-boilinghydrocarbons such as cyclopentane, isopentane, n-pentane, and theirmixtures. Other suitable blowing agents include compounds, for examplewater, that react with isocyanate compounds to produce a gas. The amountof BA is typically from about 0 (water blown) to about 80 pphp. Water(blow foam by reacting with isocyanate making CO2) can be present in therange from about 0 (if a BA is included) to about 60 pphp (a very lowdensity foam) and typically from about 1.0 pphp to about 10 pphp and, insome cases, from about 2.0 pphp to about 5 pphp.

Other Optional Components

A variety of other ingredients may be included in the formulations formaking foams according to the invention. Examples of optional componentsinclude, but are not limited to, cell stabilizers, crosslinking agents,chain extenders, pigments, fillers, flame retardants, auxiliary urethanegelling catalysts, auxiliary urethane blowing catalysts, transitionmetal catalysts, and combinations of any of these.

Cell stabilizers may include, for example, silicone surfactants oranionic surfactants. Examples of suitable silicone surfactants include,but are not limited to, polyalkylsiloxanes, polyoxyalkylenepolyol-modified dimethylpolysiloxanes, alkylene glycol-modifieddimethylpolysiloxanes, or any combination thereof. Suitable anionicsurfactants include, but are not limited to, salts of fatty acids, saltsof sulfuric acid esters, salts of phosphoric acid esters, salts ofsulfonic acids, and combinations of any of these.

Crosslinking agents include, but are not limited to, low-molecularweight compounds containing at least two moieties selected from hydroxylgroups, primary amino groups, secondary amino groups, and other activehydrogen-containing groups which are reactive with an isocyanate group.Crosslinking agents include, for example, polyhydric alcohols(especially trihydric alcohols, such as glycerol andtrimethylolpropane), polyamines, and combinations thereof. Non-limitingexamples of polyamine crosslinking agents include diethyltoluenediamine,chlorodiaminobenzene, diethanolamine, diisopropanolamine,triethanolamine, tripropanolamine, 1,6-hexanediamine, and combinationsthereof. Typical diamine crosslinking agents comprise twelve carbonatoms or fewer, more commonly seven or fewer.

Examples of chain extenders include, but are not limited to, compoundshaving hydroxyl or amino functional group, such as glycols, amines,diols, and water. Specific non-limiting examples of chain extendersinclude ethylene glycol, diethylene glycol, propylene glycol,dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol,neopentyl glycol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol,ethoxylated hydroquinone, 1,4-cyclohexanediol, N-methylethanolamine,N-methylisopropanolamine, 4-aminocyclohexanol, 1,2-diaminoethane,2,4-toluenediamine, or any mixture thereof.

Pigments may be used to color code the polyurethane foams duringmanufacture, for example to identify product grade or to concealyellowing. Pigments may include any suitable organic or inorganicpigments known in the polyurethane art. For example, organic pigments orcolorants include, but are not limited to, azo/diazo dyes,phthalocyanines, dioxazines, and carbon black. Examples of inorganicpigments include, but are not limited to, titanium dioxide, iron oxides,or chromium oxide.

Fillers may be used to increase the density and load bearing propertiesof polyurethane foams. Suitable fillers include, but are not limited to,barium sulfate or calcium carbonate.

Flame retardants may be used to reduce the flammability of polyurethanefoams. For example, suitable flame retardants include, but are notlimited to, chlorinated phosphate esters, chlorinated paraffins, ormelamine powders.

Cell stabilizers can used in an amount from about 0.1 to about 20 pphpand typically from about 0.1 to about 10 pphp and, in some cases, fromabout 0.1 to about 5.0 pphp. Fire retardants can be used in an amountfrom about 0 to about 20 pphp and from about 0 to about 10 pphp and fromabout 0 to about 5 pphp. All other additives are typically used inamounts ranging from about 0.1 pphp to about 20 pphp

The following Examples are provided to illustrate certain aspects of theinvention and shall not limit the scope of the claims appended hereto.

EXAMPLES

Listed are the TDI based polyurethane foam formulations which were usedto evaluate the cell openers and cell opener aids using conventionalacid blocked or non-blocked tertiary amine catalysts in free-rise andmolded foams. Foam pads were removed from the heated mold and allowed tocool down to room temperature to monitor dimensional stability(shrinkage).

Handmix Evaluations

Handmix experiments were conducted using the following procedure.Formulations were blended together for approximately 10 minutes using amechanical mixer equipped with a 7.6 cm diameter high shear mixingblade, rotating at 5000 rpm. Premixed formulations were maintained at23±1° C. using a low temperature incubator. Mondur TD-80 (an 80/202,4/2,6 isomer blend of toluene diisocyanate) or modified MDI was addedto the premix at the correct stoichiometric amount for the reportedindex of each foam. The mixture was blended together with Premier MillCorporation Series 2000, Model 89, and dispersed for approximately fiveseconds. The foaming mixture was transferred to an Imperial Bondware#GDR-170 paper bucket and allowed to free rise while data was recorded.

Machine Evaluations

Machine runs for the flexible molded foam were conducted on a Hi TechSure Shot MHR-50, cylinder displacement series and high-pressuremachine. Fresh premixes, consisting of the appropriate polyols, water,crosslinker, surfactants and catalysts for each formulation were chargedto the machine. Mondur TD-80 was used throughout the entire study. Allchemical temperatures were held at 23±2° C. via the machine's internaltemperature control units. Foam pours were made into an isothermallycontrolled, heated aluminum mold maintained at 63±2° C. The mold was atypical physical property tool designed with internal dimensions of 40.6cm×40.6 cm×10.2 cm. The mold has five vents, each approximately 1.5 mmin diameter, centered in each corner 10.0 cm from each edge and thegeometric center of the lid. The mold was sprayed with a solvent-basedrelease agent, prior to every pour and allowed to dry for one minutebefore pouring. The foam premix was puddle poured into the center of themold with a wet chemical charge weight capable of completely filling themold and obtaining the desired core densities reported. Minimum fillrequirements were established for each formulation evaluated. The foamarticle was demolded at 240 seconds (4 minutes) after the initial pour(detailed in next paragraph). Upon demold, the foam was placed through amechanical crusher or tested for Force-to-Crush (FTC) measurements orallow to cool down to determine dimensional stability (detailed below).

Foam physical properties of each catalyst set were mechanically crushed1 minute after demold using a Black Brothers Roller crusher set to a gapof 2.54 cm. Crushing was conducted three times on each part, rotatingthe foam 90 degrees after each pass through the rollers. All partsproduced for physical testing were allowed to condition for at leastseven days in a constant temperature and humidity room (23±2° C., 50±2%relative humidity).

FTC measurements were conducted 45 seconds after demold. The pad wasremoved from the mold, weighed and placed in the FTC apparatus. Theforce detection device is equipped with a 2.2 kg capacity pressuretransducer mounted between the 323 cm² circular plate cross head and thedrive shaft. The actual force is shown on a digital display. This devicemimics the ASTM D-3574, Indentation Force Deflection Test and provides anumerical value of freshly demolded foam's initial hardness or softness.The pad was compressed to 50 percent of its original thickness at across-head velocity of 275 mm per minute with the force necessary toachieve the highest compression cycle recorded in Newton's. Tencompression cycles were completed. A cycle takes approximately 30seconds to complete.

Example 1 Use of Cell Opening Aids to Minimize Cell Opening Use Levels

Foam pads were prepared by adding a tertiary amine catalyst to about 302g of a premix (prepared as in Table 2) in a 32 oz (951 ml) paper cup.The formulation was mixed for about 10 seconds at about 6,000 RPM usingan overhead stirrer fitted with a 2-inch (5.1 cm) diameter stirringpaddle.

The toluene diisocyanate was then added, and the formulation was mixedwell for about another 6 seconds at about 6,000 RPM using the samestirrer, after which it was poured into a pre-heated mold at 70° C. anddemolded after 4 minutes. The foam pads were removed from the mold, handcrushed, weighed and machine crushed at 75% pad thickness. Dimensionalstability (foam shrinkage) was evaluated by allowing the foam pads tocool down and observing whether shrinkage or not took place. Foam padswere stored under constant temperature and humidity conditions for 48hours before being cut and tested.

TABLE 2 Premix Components Component Parts by weight Hyperlite E848¹ 100Water 3.7 DABCO ® DC5164² 0.10 DABCO ® DC5169³ 0.60 DABCO ®33LX⁴ 0.30DABCO ®BL11⁵ 0.10 Diethanolamine-LF (crosslinker) 1.04 Toluenediisocyanate To provide NCO index = 100 ¹High functionality cappedpolyether polyol of high molecular weight, functionality, and primaryhydroxyl content with a base polyol molecular weight of about 5500,available from Dow Chemical Company, Midland, MI ^(2, 3)Siliconesurfactant available from Air Products and Chemicals, Inc. ^(4, 5)Aminecatalyst available from Air Products and Chemicals, Inc.

Column 1 and 2 in table 3 shows that in the absence of a cell openingaide unstable foam is produced when the level of 2-cyanoacetamide is≦0.045 PPHP. Poor dimensional stability was also observed when usingdiols such as 2-methylpropanediol (MP-diol), dipropylene glycol anddiethylene glycol as cell opening aids in the presence of 0.03 pphp of2-cyanoacetamide. However, use of aides such as DMSO, DMI, sulfolane,PEG-200, MMAA, and DMAA, helped 2-cyanoacetamide to be an effective cellopener when used at 0.030 pphp. Thus, a 30% reduction in use level wasachieved when using cell opening aids.

TABLE 3 Dimensional Stability Results 1 2 3 4 5 6 7 8 9 10 ComponentPPHP PPHP PPHP PPHP PPHP PPHP PPHP PPHP PPHP PPHP Dabco ® 33LV 0.30 0.300.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Dabco ® BL11 0.10 0.10 0.10 0.100.10 0.10 0.10 0.08 0.08 0.08 Cell Opener ≦0.040 0.045 0.030 0.030 0.0300.030 0.030 0.03 0.030 0.030 (Cyano- acetamide) Aide None None DPG DEGMP-diol DMI DMSO Sulfolane MMAA DMAA — — 0.20 0.20 0.20 0.12 0.12 0.120.12 0.12 Formic Acid 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01Ext. Time 53 52 51 52 51 51 50 53 47 48 SGT 64 66 63 66 65 63 65 64 6465 Mold Pressure N N N Y N N N N N N Dimensional Un- Stable Un- Un- Un-Stable Stable Stable Stable Stable Stability stable stable stable stableCollapse N N N N N N N N N N

Example 2 Use of Cell Opening Aids to Minimize Cell Opening Use Levels

Table 4 shows the results when 2-cyanoacetamide was used in the presenceof pentamethyldiethylenetriamine blowing catalyst and triethylenediaminegelling catalyst. As previously shown poor dimensional stability wasobserved when using typical diols such as 2-methylpropanediol (MP-diol),dipropylene glycol and diethylene glycol as cell opening aids. Bestdimensional stability was observed when PEG-200, DMSO, DMI, andsulfolane were used.

TABLE 4 Dimensional Stability Results 1 2 3 4 5 6 7 Component PPHP PPHPPPHP PPHP PPHP PPHP PPHP Dabco ® 0.30 0.30 0.30 0.30 0.30 0.30 0.30 33LVPolycat ®-5 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Cell Opener 0.050 0.0500.050 0.050 0.050 0.050 0.050 (Cyanoacetamide) Aide DPG DEG MP-diolPEG-200 Sulfolane DMSO DMI 0.45 0.28 0.45 0.16 0.16 0.16 0.16 FormicAcid 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Ext. Time 56 55 56 57 57 56 58SGT 67 69 69 66 69 66 67 Mold N Y N N N N N Pressure DimensionalUnstable Unstable Unstable Stable Stable Stable Stable Stability Foam NN N N N N N Collapse

Example 3 Use of Cell Opening Aids to Minimize Cell Opening Use Levels

Table 5 illustrates how mixtures of solvent aides could also help inimproving the performance of a cell opener. Using a polar aproticsolvent mixture (such as DMSO and propylene carbonate) helped providingdimensionally stable foam. On the other hand, the introduction ofdiethylene glycol resulted in foam shrinkage.

TABLE 5 Dimensional Stability Results Component 1 2 3 4 Dabco ® 33LV0.30 0.30 0.30 0.30 Dabco ® BL11 0.10 0.10 0.10 0.10 Cell Opener 0.0700.07 0.07 0.07 (Cyanoacetamide) Aide 1 DMSO DMSO DMSO DMSO 0.04 0.040.04 0.04 Aide 2 DEG DEG Propylene Propylene 0.07 0.07 CarbonateCarbonate 0.05 0.04 Formic Acid 0.01 — — — Acetic Acid — 0.02 0.02 0.02Ext. Time ~52 ~52 ~52 ~52 SGT ~64 ~64 ~64 ~64 Mold Pressure N N N YDimensional Stability Unstable Unstable Stable Stable Foam Collapse N NN N

Example 4 Use of Cell Opening Aids to Minimize Cell Opening Use Levels

Table 6 illustrates that cell opening aides have similar effect on2-cyanoacetamide when using non-acid blocked amine catalysts yieldingthe same results as described in the previous examples.

TABLE 6 Dimensional Stability Results 1 2 3 4 5 6 7 Component PPHP PPHPPPHP PPHP PPHP PPHP PPHP Dabco ® 0.30 0.30 0.30 0.30 0.30 0.30 0.30 33LVDabco ® 0.10 0.10 0.10 0.10 0.10 0.10 0.10 BL11 Cell Opener 0.035 0.0350.035 0.035 0.035 0.035 0.035 (Cyanoacetamide) Aide DPG DEG MP-diolPEG-200 Sulfolane DMSO DMI 0.13 0.13 0.13 0.13 0.13 0.13 0.13 Ext. Time53 51 51 57 57 56 58 SGT 64 62 64 66 69 66 67 Mold N N N N N N NPressure Dimensional Unstable Unstable Unstable Stable Stable StableStable Stability Collapse N N N N N N N

Example 5 Use of Cell Opening and Cell opening Aids to Optimize PhysicalProperties of Natural Oil Polyol Containing Polyurethane Foam

Table 7 illustrates that 12% solution of 2-cyanoacetamide dissolved inN-methylacetoacetamide and added to polyurethane foam formulationscontaining natural oil polyols help providing foam with better physicalproperties such as ILDs as well as tensile, tear and elongation. Theutilization of a solution of 2-cyanoacetamide in a polyurethaneformulation can help maximizing the utilization of natural oil polyolsincreasing the renewable content of the finished product.

TABLE 7 Physical Properties Component/Property Units Control NOPPolycat ®-15 PPHP 0.49 0.49 Dabco ® BL11 PPHP 0.10 0.10 12% solution of2-Cyanoacetamide PPHP — 0.75 in N-monomethylacetoacetamide TDI Index %100 100 Density Kg/m3 40 40 Air Flow SCFH 3.8 3.7 Tear N/m 313 360Tensile kPa 131 144 Elongation % 91 96 ILD 25% N 149 224 ILD 65% N 389474 ILD 25% return N 118 167

While the invention has been described with reference to certain aspectsor embodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt the teachings of theinvention without departing from the essential scope thereof. Therefore,it is intended that the invention not be limited to the particularembodiment disclosed as the best mode contemplated for carrying out thisinvention, but that the invention will include all embodiments fallingwithin the scope of the appended claims.

The invention claimed is:
 1. A composition comprising at least onenatural oil polyol, at least one copolymer polyol, at least one cellopener, at least one cell opener aid, and at least one tertiary aminecatalyst; wherein the cell opener comprises molecules containing activemethylene or methine groups and the cell opener aid comprises.
 2. Acomposition comprising at least one natural oil polyol,2-cyanoacetamide, at least one tertiary amine, at least one acidcomprising at least one of acetic and formic acids andN-methyl-acetoacetamide.
 3. A composition comprising at least onenatural oil polyol, 2-cyanoacetamide, at least one tertiary amine, andN-methyl-acetoacetamide.
 4. A composition consisting essentially of atleast one natural oil polyol, 2-cyanoacetamide, at least one tertiaryamine, and N-methyl-acetoacetamide.
 5. A composition consistingessentially of at least one natural oil polyol, 2-cyanoacetamide, atleast one tertiary amine, formic acid and N-methyl-acetoacetamide. 6.The composition of claim 1 wherein the cell opener comprises2-cyanoacetamide.
 7. The composition of claim 3 wherein the natural oilpolyol comprise triglycerides of saturated and unsaturated fatty acids.8. The composition of claim 3 further comprising at least one carboxylicacid.
 9. The composition of claim 3 wherein the tertiary amine comprisesat least one acid blocked tertiary amine catalyst.
 10. The compositionof claim 3 further comprising at least one of acetic acid and formicacid.
 11. The composition of claim 2 further comprising at least onecopolymer polyol.
 12. The composition of claim 3 wherein the amount of2-cyanoacetamide ranges from about 0.01 pphp to about 1.0 pphp and theamount of N-methyl-acetoacetamide ranges from about 0.05 to about 5pphp.
 13. The composition of claim 3 further comprising at least onecopolymer polyol.